AP MEYERS PSYCHOLOGY UNIT 1 KEY TERMS

Nature-Nurture Issue

Explores whether human behavior is determined by the environment, or by a person's genes.

Glial Cells (Glia)

Support cells in the nervous system that help neurons perform their functions.

Charles Darwin

Proposed the theory of natural selection and evolution, which explains how species change over time due to genetic variations that enhance survival.

Action Potential

A brief electrical surge that a neuron experiences when it fires.

Threshold

The minimum level of stimulus required to activate a neuron.

Natural Selection

Darwin's principle stating that genetic traits beneficial for survival are more likely to be passed on to future generations.

Evolutionary Psychology

Studies how natural selection has shaped behavior in humans.

Refractory Period

A short resting phase during which a neuron cannot fire again.

Behavior Genetics

The study of how much our genes and our environment influence our behavioral differences.

All-or-None Response

A neuron’s response of either firing fully or not firing at all.

Mutation

A change in a DNA sequence that affects genetic information.

Synapse

The gap between two neurons, where neurotransmitters are released to communicate information.

Environment

All the external factors that can affect behavior and development.

Neurotransmitters

Chemicals in the brain that transmit signals from one neuron to another.

Heredity

Passing of traits from parents to offspring through genes.

Reuptake

The process by which neurotransmitters are taken back into the neuron that released them.

Genes

Segments of DNA that carry genetic information.

Genome

The complete set of genetic information for an organism.

Identical (Monozygotic) Twins

Twins who develop from a single fertilized egg and share the same genes.

Fraternal (Dizygotic) Twins

Twins who develop from two different eggs and are as genetically similar as regular siblings.

Endocrine System

Glands that produce hormones and help regulate body functions.

Interaction

The effect of one factor (like environment) depends on another factor (like heredity).

Epigenetics

The study of environmental influences on gene expression that occur without a DNA change.

Hormones

Chemicals produced by endocrine glands that regulate processes such as growth and mood.

Nervous System

The network of nerve cells and fibers that transmits nerve impulses between parts of the body.

Central Nervous System (CNS)

Consists of the brain and spinal cord.

Peripheral Nervous System (PNS)

The sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundles of fibers that transmit information between the brain and other parts of the body.

Sensory (Afferent) Neurons

Neurons that carry messages from the body's organs and tissues to the central nervous system.

Motor (Efferent) Neurons

Neurons that carry signals from the central nervous system to the muscles and glands.

Interneurons

Neurons that connect sensory neurons, motor neurons, or other interneurons.

Somatic Nervous System

Part of the peripheral nervous system that controls voluntary movements.

Autonomic Nervous System (ANS)

Controls involuntary body functions like heartbeat and digestion.

Sympathetic Nervous System

Activates the body in emergency situations (fight or flight).

Parasympathetic Nervous System

Helps the body conserve energy and maintain quiet state functions.

Reflex

An automatic response to a sensory stimulus.

Neuron

A nerve cell that is the basic building block of the nervous system.

Cell Body

The part of a neuron that contains the nucleus and connects to the dendrites, which bring information to the neuron, and the axon, which sends information to other neurons.

Dendrites

The branches of a neuron that receive messages and conduct impulses toward the cell body.

Axon

The long, thin fiber that transmits signals away from the neuron's cell body.

Myelin Sheath

A layer of fatty tissue that covers many axons and helps speed neural impulses.

EEG (Electroencephalogram)

A test that measures the electrical activity of the brain.

PET (Positron Emission Tomography) Scan

A brain scan that uses a radioactive tracer to visualize brain activity.

MRI (Magnetic Resonance Imaging)

A technique that uses magnetic fields and radio waves to produce images of the brain and other body parts.

fMRI (Functional MRI)

A type of MRI that shows changes in brain activity by detecting blood flow.

Hindbrain

The lower part of the brain that is involved in vital functions such as heart rate and balance.

Midbrain

A small central part of the brainstem that integrates sensory information.

Forebrain

The largest and most complex part of the brain, including the thalamus, hypothalamus, limbic system, and cerebral cortex.

Brainstem

The oldest part of the brain, responsible for automatic survival functions.

Medulla

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion.

Thalamus

The brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex.

Reticular Formation

A nerve network in the brainstem that plays an important role in controlling arousal.

Cerebellum

A large structure of the hindbrain that controls fine motor skills.

Limbic System

A system of neural structures at the edge of the brainstem; involved in motivation, emotion, learning, and memory.

Amygdala

Two almond-shaped neural clusters in the limbic system linked to emotion.

Hypothalamus

A neural structure lying below (hypo) the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion.

Hippocampus

A neural center located in the limbic system; helps process explicit memories for storage.

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center.

Frontal Lobes

Involved in speaking, muscle movements, and making plans and judgments.

Parietal Lobes

Receives sensory input for touch and body position.

Occipital Lobes

Includes areas that receive information from the visual fields.

Temporal Lobes

Includes the auditory areas, each receiving information primarily from the opposite ear.

Motor Cortex

An area at the rear of the frontal lobes that controls voluntary movements.

Somatosensory Cortex

Area at the front of the parietal lobes that registers and processes body touch and movement sensations.

Association Areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions; they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Neurogenesis

The formation of new neurons.

Corpus Callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Roger Sperry

Nobel laureate best known for his pioneering research on the split-brain.

Michael Gazzaniga

A psychologist who conducted extensive research on the split-brain.

Split Brain

A condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

Consciousness

Our awareness of ourselves and our environment.

Cognitive Neuroscience

The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language).

Dual Processing

The principle that our mind processes information at both the conscious and unconscious levels.

Blindsight

A condition in which a person can respond to a visual stimulus without consciously experiencing it.

Parallel Processing

The processing of many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions.

Sequential Processing

The processing of one aspect of a problem at a time; used when we focus attention on new or complex tasks.

Sleep

A periodic, natural loss of consciousness—as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.

Circadian Rhythm

The biological clock; regular bodily rhythms that occur on a 24-hour cycle.

REM Sleep

Rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur.

Alpha Waves

The relatively slow brain waves of a relaxed, awake state.

NREM Sleep

Non-rapid eye movement sleep; encompasses all sleep stages except for REM sleep.

Hallucinations

False sensory experiences, such as seeing something in the absence of an external visual stimulus.

Hypnagogic Sensations

Sensations of falling or floating that are sometimes experienced during the onset of sleep.

Delta Waves

The large, slow brain waves associated with deep sleep.

Suprachiasmatic Nucleus (SCN)

A pair of cell clusters in the hypothalamus that controls circadian rhythm.

Insomnia

Recurring problems in falling or staying asleep.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks.

Sleep Apnea

A sleep disorder where breathing repeatedly stops and starts during sleep, causing poor sleep quality.

REM Sleep Behavior Disorder

A sleep disorder in which a person acts out vivid dreams during REM sleep, often involving physical movement.

Dream

A series of thoughts, images, and sensations occurring in a person's mind during sleep.

Sigmund Freud

A neurologist and the founder of psychoanalysis, who theorized that unconscious motivations influence behavior.

REM Rebound

The tendency for REM sleep to increase following REM sleep deprivation.

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Sensory Receptors

Specialized cells responsible for converting external stimuli into neural activity for a specific sensory system.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-Up Processing

An approach wherein sensory information is analyzed in its most basic form without preconceived cognitive interpretation.

Top-Down Processing

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Transduction

The conversion of one form of energy into another. In sensory processing, it refers to transforming stimuli detected by sensory receptors into neural impulses.

Psychophysics

The study of relationships between the physical characteristics of stimuli and the psychological experience of them.

Gustav Fechner

A psychologist and philosopher who founded psychophysics and proposed the Weber-Fechner law, which quantifies the perception of changes in stimulus intensity.